Netgear R6300v2 connection problem

Hi,

I have Spectrum Provider and Netgear router R6300v2. The router has been updated to the latest firmware and connects to my Netgear CM500 modem. 

My laptop is hard-wired with CAT6 cable to the router. The problem is the router has a good connection and full speed, but only gives me access to some websites: Google, Youtube, Facebook, Wiki, but the other websites cannot be accessed, even the applications need online access. I tried to connect via Wifi but the same issue. I can use Windows Update neither.

I connected my laptop straight to the modem, everything works very well. I even used my phone network as a hotspot for my laptop, good connection, and able to access everything.

I connected my phone to the router's wifi and everything is normal.

Not only my laptop but the other computers/laptops around my house have the same problem.

I tried different methods like factory reset the router + modem, power cycle, changing router's DNS to 8.8.8.8 and 8.8.4.4. Nothing works to the router.

I called Netgear Customer Support and they said my router is out of warranty and need to buy a Warranty Package from them so they can provide the specific solution.

Please help.